The present invention relates to structures for holding underwater projections such as the struts of hydrofoil craft with submerged foils.
Underwater projections projecting downward from the bottoms of hulls, such as struts of submerged hydrofoils and outboard engines of small boats, are usually fixed to the hull so as to remain projected as specified against the water pressure acting thereon during navigation.
When the underwater projection of the above conventional structure collides with an obstacle, the projection or the projection attaching portion of the hull becomes damaged or broken since the projection is firmly attached to the hull. The conventional structure therefore has the problem of necessitating much time and labor for the repair.
On the other hand, proposals have been made to avoid the damage to the hull by providing shock absorbing means which is adapted to permit the underwater projection to escape rearward when the projection is subjected to a force exceeding a certain magnitude. However, the structure concerned becomes very large, complex and expensive since it must be adapted to usually hold the projection in its fixed position against great forces but to perform the shock absorbing function only when a further greater force acts on the projection.